From the linked Wired article:

The PGP key associated with Nakamoto’s email address and references to an upcoming “cryptocurrency paper” and “triple entry accounting” were added sometime after 2013.

Gwern's comment in the Reddit thread:

[...] this is why we put our effort into nailing down the creation and modification dates of the blog post in third-party archives like the IA and Google Reader.

These comments seem to partly refer to the 2013 mass archive of Google Reader just before it was discontinued. For others who want to examine the data: the relevant WARC records for gse-compliance.blogspot.com are in line 110789824 to line 110796183 of greader_20130604001315.megawarc.warc, which is about three-quarters of the way into the file. I haven't checked the directory and stats grabs and don't plan to, as I don't want to spend any more time on this.

NB: As for any other large compressed archives, if you plan on saving the data, then I suggest decompressing the stream as you download it and recompressing into a seekable structure. Btrfs with compression works well, but blocked compression implementations like bgzip should also work in a pinch. If you leave the archive as a single compressed stream, then you'll pull all your hair out when you try to look through the data.